The object of the proposed work is to establish human tumor cells in immunosuppressed animals and in culture. Special effort will be made to establish hormone dependent cells in culture with maintenance of hormone dependency. The bulk of the effort will be devoted toward androgen dependent prostatic tumors. Techniques will be developed to permit the transplantation of human tumors in appropriately conditioned animal hosts. Tissue culture techniques will be developed to select against connective tissue fibroblast and to specifically promote the growth of the desired cell type.